JPH04278153A - Cooling and heating device - Google Patents

Abstract

PURPOSE:To carry out a continuous operation without stopping any heating operation even under a defrosting state. CONSTITUTION:In the case that an outdoor heat exchanger 61 is frosted during a heating operation, a frosting sensor 62 detects this state, a control devices 45 causes an air blowing fan to decrease an amount of blowing air for an indoor heat exchanger 29 and to decrease its amount of thermal radiation. Concurrently, throttling of an expansion valve 67 is released. With such an arrangement, refrigerant discharged out of the indoor heat exchanger 29 becomes two gas-liquid phases and is not adjusted and then the refrigerant is sent to an outdoor heat exchanger 61 as it is and then its defrosting operation is carried out.

Description

[Detailed description of the invention]

[Object of the invention]

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a heating and cooling system that combines a refrigeration cycle and a refrigerant heater.

0003

[Prior Art] In general, a heat pump type air-conditioning system, which has a refrigeration cycle composed of a compressor, an indoor heat exchanger, an outdoor heat exchanger, an expansion valve, etc., uses a refrigerant after heat radiation in an indoor heat exchanger during heating. After reducing the pressure with an expansion valve, the outdoor heat exchanger absorbs atmospheric heat, vaporizes it, and sends it to the compressor. In such a heat pump type, the refrigerant receives heat from the atmosphere in an outdoor heat exchanger and vaporizes it.
When the outside air temperature is low, there is a drawback that the heating capacity decreases even though it is originally necessary to increase the heating capacity. For this reason, conventionally, there is a refrigerant-heating type air-conditioning/heating device in which a refrigerant heater is added to the heat pump type refrigeration cycle to improve the heating capacity. In an air-conditioning/heating machine that operates refrigerant heating and a heat pump at the same time, there is an example in which a two-cylinder compressor 1 is used, as shown in the refrigeration cycle configuration shown in FIG. The main components are a two-cylinder compressor 1, a four-way valve 3, an indoor heat exchanger 5, an outdoor heat exchanger 7, a refrigerant heater 9,
Various valves include an expansion valve 11, a two-way valve 13, a flow control valve 15, a check valve 17, and the like. This compressor 1 includes a first cylinder 19 and a second cylinder 21, each cylinder 19, 21 being operated simultaneously by one motor 23.

[0004] In a heating and cooling system having such a configuration,
During heating, when refrigerant heating and heat pump are operated simultaneously, the refrigerant flows from the compressor 1 to the four-way valve 3 to the indoor heat exchanger 5, and after leaving the indoor heat exchanger 5, it branches into two. ,
One side passes through the refrigerant heater 9 to the first cylinder 1 of the compressor 1.
9, and the other passes through the expansion valve 11 and the outdoor heat exchanger 7 to the second
It flows into the cylinder 21. At this time, the two-way valve 13 is in an open state, the flow control valve 15 is in a wide open state, and there is virtually no pressure loss. Further, when only the heat pump is operated without operating the refrigerant heater 9, the two-way valve 13 is closed. At this time, the refrigerant does not circulate through the refrigerant heater 9. During cooling, the refrigerant flows in the order of compressor 1 → four-way valve 3 → outdoor heat exchanger 7 → expansion valve 11 → indoor heat exchanger 5 → four-way valve 3 → compressor 1. At this time as well, the two-way valve 11 is closed, and no refrigerant flows into the refrigerant heater 9.

In such a configuration, when the refrigerant heater 9 is in operation, the suction line on the refrigerant heater 9 side is at high pressure, so the first cylinder 19 is used for the refrigerant heater 9.
The second cylinder 21 is used for the outdoor heat exchanger 7, that is, for operating the heat pump. Furthermore, when the two-way valve 11 is closed and the refrigerant heater 9 is not operated, the suction line on the refrigerant heater 9 side is lower than the outdoor heat exchanger 7 side, so that the refrigerant passes through the check valve 17. Become. That is,
This means that the heat pump operation is performed using two cylinders 19 and 21.

[0006]

[Problems to be Solved by the Invention] By the way, in the air conditioning system configured as described above, the heat pump operation using the outdoor heat exchanger 7 is performed in any operation mode during heating, so depending on the outdoor air conditions, the outdoor heat Since frost forms on the exchanger 7, it is necessary to defrost it in that case. In order to perform the defrosting operation, the four-way valve 3 is switched to send the high-temperature discharge gas of the compressor 1 directly to the outdoor heat exchanger 7 via the four-way valve 3.

However, in this case, since the four-way valve 3 is switched, high-temperature refrigerant vapor is not sent to the indoor heat exchanger 5, so the heating operation is temporarily stopped, resulting in a comfortable heating sensation for the user. This makes it difficult to obtain.

[0008] Therefore, an object of the present invention is to enable the heating operation to continue without stopping even during defrosting.

[Configuration of the invention]

0010

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention has two cylinder parts each having two suction ports and one discharge port, and two cylinder parts that operate simultaneously corresponding to each suction port. A compressor, an indoor heat exchanger installed indoors,
an outdoor heat exchanger installed outdoors, a switching valve that connects each of the indoor heat exchangers and the outdoor heat exchanger to the discharge port and one suction port of the compressor, and a switching valve that connects the indoor heat exchanger and the outdoor heat an expansion valve provided in a pipe connecting the exchanger; a refrigerant heater provided between the pipe and the other suction port of the compressor;
A frost formation detection means for detecting frost formation on the outdoor heat exchanger during heating, and a control means for reducing the heat radiation amount of the indoor heat exchanger by a predetermined amount when the frost formation detection means detects frost formation. There is a configuration that has.

[0011] The present invention also provides a compressor having two suction ports and one discharge port, and two cylinder sections that operate simultaneously corresponding to each suction port, and an indoor heating system installed indoors. an exchanger, an outdoor heat exchanger installed outdoors, a switching valve connecting each of the indoor heat exchangers and the outdoor heat exchanger to a discharge port and one suction port of the compressor, and the indoor heat exchanger. frost builds up on the expansion valve provided in the piping connecting the outdoor heat exchanger and the refrigerant heater provided between the piping and the other suction port of the compressor, and on the outdoor heat exchanger during heating. The refrigerant heater may be configured to include a frost detection means for detecting frost formation, and a control means for increasing the capacity of the refrigerant heater by a predetermined amount when the frost formation detection means detects frost formation.

0012

[Operation] When frost forms on the outdoor heat exchanger during heating, the frost formation detection means detects this, and this detection signal is input to the control means. Thereby, the control means controls the indoor heat exchanger to reduce the amount of heat released by a predetermined amount. When the amount of heat released by the indoor heat exchanger decreases, the refrigerant leaving the indoor heat exchanger becomes completely uncondensed and becomes a gas-liquid two-phase state, and this refrigerant is sent to the outdoor heat exchanger to remove accumulated frost. During defrosting, the amount of heat dissipated from the indoor heat exchanger is only reduced, and the switching valve is not switched, and the heating operation continues, providing a comfortable feeling of heating.

Further, in the present invention, when frost forms on the outdoor heat exchanger during heating, the frost formation detection means detects this, and this detection signal is inputted to the control means. Thereby, the control means controls the refrigerant heater to increase its capacity by a predetermined amount. As the capacity of the refrigerant heater increases, the refrigerant that exits the indoor heat exchanger after being discharged from the compressor becomes a gas-liquid that does not completely condense.
This refrigerant is sent to the outdoor heat exchanger to remove the frost that has adhered to it. During defrosting, the capacity of the refrigerant heater is simply increased, and heating operation continues without switching the switching valve.Furthermore, there is no decrease in the amount of heat released by the indoor heat exchanger, resulting in more comfortable heating. You can feel it.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings.

FIG. 1 shows a refrigeration cycle configuration of a heating and cooling system according to a first embodiment of the present invention. The components are described in the order in which the refrigerant flows during heating: a two-cylinder compressor 25, a four-way valve 27 as a switching valve, and an indoor heat exchanger 29. The compressor 25 houses two first cylinders 31 and a second cylinder 33 as cylinder parts, and includes one discharge port 35 and two suction ports 37 and 39. It is assumed that both cylinders 31 and 33 are operated simultaneously by a motor (not shown). The indoor heat exchanger 29 is built into an indoor unit (not shown), and the indoor unit is provided with a blower fan 41 that sends air to the indoor heat exchanger 29. The blower fan 41 is rotated by a motor 43, and the motor 43 is connected to a control unit 4 as a control means composed of, for example, a microcomputer.
5 controls the rotation speed.

The discharge port 35 of the compressor 25 and the four-way valve 27 are connected by a pipe 47, and the four-way valve 27 and the indoor heat exchanger 29 are connected by a pipe 49. The refrigerant that has exited the indoor heat exchanger 29 flows through a pipe 51 and is then branched into two systems at a branching part 53, one of which goes to the refrigerant heater 57 through a pipe 55, and the other goes to the outdoor heat exchanger 61 through a pipe 59. flows to the side. The refrigerant heater 57 includes a refrigerant heating heat exchanger 63 and a burner section 65. The piping 59 is provided with an expansion valve 67, which functions to lower the pressure of the refrigerant to an evaporation pressure that can absorb heat from the atmosphere during heat pump operation, and the valve opening degree is controlled by the control unit 45. .

Further, the outdoor heat exchanger 61 is provided with a frost sensor 62 as a frost detection means for detecting frost adhering to the surface of the outdoor heat exchanger 61 during heating operation. The detection signal of the frost sensor 62 is output to the control unit 45, and upon receiving this signal input, the control unit 45 lowers the rotation speed of the motor 43 of the blower fan 41 to reduce the heat radiation amount of the indoor heat exchanger 29. At the same time, the throttle opening degree of the expansion valve 67 is loosened. The amount by which the amount of heat radiation is reduced is such that the refrigerant exiting the indoor heat exchanger 29 is in a two-phase state of a gas phase and a liquid phase without being completely condensed.

A two-way valve 69 is provided in the piping 55 on the upstream side of the refrigerant heater 57, and this two-way valve 69 is used when the refrigerant heater 57 is not used when the heat pump is operated only during heating, or when the refrigerant is heated during cooling. The flow path is closed when the vessel 57 is not used. The refrigerant that has exited the refrigerant heater 57 flows into a pipe 71 , and this pipe 71 is connected to the first cylinder 31 of the compressor 25 via the suction port 37 . The outdoor heat exchanger 61 and the four-way valve 27 are connected by a pipe 73, and the four-way valve 27 and the compressor 25
It is connected to the suction port 39 of the second cylinder 33 by a pipe 75.

In the above configuration, when the heating capacity is large, the refrigerant heating and the heat pump operate simultaneously, but in this case, the two-way valve 69 is in an open state. Refrigerant heater 57
The refrigerant vapor that exits is under high pressure and is sent to the first cylinder 31 via the pipe 71. On the other hand, outdoor heat exchanger 6
The refrigerant vapor exiting the refrigerant 1 is at a low pressure and is sent to the second cylinder 33 via the pipe 73, the four-way valve 27, and the pipe 75. Further, when the heating capacity is small, only the heat pump is operated, and in this case, the two-way valve 69 is closed.

During such a heating operation, if the outside air temperature drops and frost forms on the outdoor heat exchanger 61, a defrosting operation is started. Control unit 45 at this time
A flowchart showing the control operation is shown in FIG. first,
It is determined whether the frost sensor 62 detects frost adhesion to the outdoor heat exchanger 61 (step 201). Here, if the frost formation sensor 62 detects the adhesion of frost, the rotation speed of the motor 43 is lowered by a predetermined amount to reduce the amount of air blown by the ventilation fan 41, and the amount of heat dissipated from the indoor heat exchanger 29 is reduced by a predetermined amount. (Step 203), and the opening degree of the expansion valve 67 is increased (Step 205). Indoor heat exchanger 2
When the heat radiation amount of 9 decreases by a predetermined amount, the refrigerant is transferred to the indoor heat exchanger 2.
The gas is not completely condensed in the tube 9 and becomes a gas-liquid two-phase state of gas and liquid, and flows out into the pipe 51. Then, the gas phase refrigerant is sent as it is to the outdoor heat exchanger 61 without being throttled by the expansion valve 67, and the frost attached to the surface of the outdoor heat exchanger 61 is melted by the latent heat of the high-pressure refrigerant vapor. In step 201, if the frost sensor 62 does not detect frost, normal operation continues (step 207).
.

During the defrosting operation as described above, the switching valve 2
The refrigerant gas discharged from the compressor 25 without switching the
Since the heat is sent to the indoor heat exchanger 29 in the same way as during the heating operation, the heating operation is not stopped and the user can continue to enjoy a comfortable feeling of heating.

[0022] In the above embodiment, the indoor heat exchanger 29
In order to reduce the amount of heat dissipated, the rotation speed of the ventilation fan 41 is lowered. It is also possible to reduce the amount of heat dissipated by reducing the amount of heat dissipated.

FIG. 3 shows a refrigeration cycle configuration of a heating and cooling system according to a second embodiment of the present invention. In this embodiment, during defrosting operation, the capacity of the refrigerant heater 57 is increased by a predetermined amount until all of the latent heat of the refrigerant in the indoor heat exchanger 29 can be radiated.
This prevents the refrigerant gas discharged from the indoor heat exchanger 29 from being completely condensed. In this case, the control unit 77 receives the signal input from the defrosting sensor 62.
controls the operation of the motor 81 that rotates the combustion air supply fan 79 to the burner section 65 and the operation of the fuel supply device 83 to the burner section 65, and at the same time controls the valve opening degree of the expansion valve 67. The rest of the structure is the same as that of the first embodiment shown in FIG. 1, and the same components as in FIG. 1 are given the same reference numerals.

In the air conditioning system having the above configuration, the control unit 77 is used when the outside air temperature drops and frost forms on the outdoor heat exchanger 61 during simultaneous heating operation using refrigerant heating and the heat pump, or during heating operation using only the heat pump. The control operation will be explained based on the flowchart of FIG.

First, the frost sensor 62 is connected to the outdoor heat exchanger 61.
It is determined whether frost has been detected (step 301). Here, if the frost sensor 62 detects the adhesion of frost, the amount of fuel supplied by the fuel supply device 83 is increased, and at the same time, the rotation speed of the motor 81 is increased to increase the amount of air blown by the combustion air supply fan 79. and thereby increase the capacity of the refrigerant heater 57 (step 30
3). Furthermore, the throttle opening degree of the expansion valve 67 is increased (step 305). When the capacity of the refrigerant heater 57 increases by a predetermined amount, the refrigerant discharged from the compressor 25 is transferred to the indoor heat exchanger 2.
9, the heat cannot be dissipated by the increased capacity, and the gas and liquid become a gas-liquid two-phase state without being completely condensed and flow out into the pipe 51. Then, the gas phase refrigerant is sent as it is to the outdoor heat exchanger 61 without being throttled by the expansion valve 67, and the frost attached to the surface of the outdoor heat exchanger 61 is melted by the latent heat of the high-pressure refrigerant vapor. If the frost formation sensor 62 does not detect the adhesion of frost in step 301, normal operation continues (step 307).

During the defrosting operation as described above, the switching valve 27 is not switched and the refrigerant gas discharged from the compressor 25 is passed through the indoor heat exchanger 2 as in the heating operation.
9, the heating operation will not be stopped.
Moreover, since the amount of heat released by the indoor heat exchanger 29 is the same as during normal heating operation, the user can continue to enjoy a more comfortable feeling of heating.

FIG. 5 shows a refrigeration cycle configuration of a heating and cooling system according to a third embodiment of the present invention. In this embodiment, in the refrigeration cycle shown in FIGS. 1 and 3,
A gas-liquid separator 85 is provided at a branch section 53 where the refrigerant exiting the indoor heat exchanger 29 branches during simultaneous heating operation of the refrigerant heating and the heat pump. This gas-liquid separator 85 is
It functions to flow the gas phase portion of the gas-liquid two-phase refrigerant that exits the indoor heat exchanger 29 during defrosting operation to the outdoor heat exchanger 61. The other configurations are the same as those in FIG. 1 or 3,
The same components as in FIGS. 1 and 3 are given the same reference numerals. However, the defrost control circuit comprised of a defrost sensor, a control unit, etc. is omitted here.

[0028] In the air-conditioning device having such a configuration,
During defrosting operation, the gas-liquid two-phase refrigerant that exits the indoor heat exchanger 29 passes through the gas-liquid separator 85, and only the gas phase is transferred to the indoor heat exchanger 6.
1 to efficiently remove frost, while the liquid phase is sent to a refrigerant heater 57. Thereby, the amount of liquid refrigerant coming out of the outdoor heat exchanger 61 can be minimized, and so-called liquid back, in which the liquid refrigerant flows into the compressor 25, can be suppressed.

[0029]

[Effects of the Invention] As explained above, according to the present invention, when frost adheres to the outdoor heat exchanger, the heat radiation amount of the indoor heat exchanger is reduced by a predetermined amount, or the capacity of the refrigerant heater is reduced. By increasing the amount by a predetermined amount, the refrigerant leaving the indoor heat exchanger enters a gas-liquid two-phase state that is not completely condensed, and the latent heat of the gas phase in this state removes the frost that has adhered to the outdoor heat exchanger. Can be removed. At this time, the refrigerant discharged from the compressor is flowing into the indoor heat exchanger, and defrosting is performed while the heating operation continues without stopping, providing a comfortable feeling of heating for the user. . Further, when the capacity of the refrigerant heater is increased by a predetermined amount, the heating capacity of the indoor heat exchanger does not decrease, and a more comfortable feeling of heating can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a refrigeration cycle showing a first embodiment of the present invention.

FIG. 2 is a flowchart showing a control operation of a control unit in the refrigeration cycle of FIG. 1;

FIG. 3 is a configuration diagram of a refrigeration cycle showing a second embodiment of the present invention.

FIG. 4 is a flowchart showing the control operation of the control unit in the refrigeration cycle of FIG. 3;

FIG. 5 is a configuration diagram of a refrigeration cycle showing a third embodiment of the present invention.

FIG. 6 is a configuration diagram of a refrigeration cycle showing a conventional example.

[Explanation of symbols]

25 Two-cylinder compressor 27 Four-way valve (switching valve) 29 Indoor heat exchanger 31 First cylinder (cylinder part) 33 Second cylinder (cylinder part) 35 Discharge ports 37, 39 Suction ports 45, 77 Control unit (control means )57
Refrigerant heater 59 Piping 61 Outdoor heat exchanger 67 Expansion valve 62 Frost sensor (frost detection means)

Claims (2)

[Claims] [Claim 1] A compressor having two suction ports and one discharge port, and two cylinder sections that operate simultaneously corresponding to each suction port, and an indoor heat exchanger installed indoors; an outdoor heat exchanger installed outdoors, a switching valve that connects each of the indoor heat exchangers and the outdoor heat exchanger to the discharge port and one suction port of the compressor, and a switching valve that connects the indoor heat exchanger and the outdoor heat Detecting frost formation on an expansion valve provided in a pipe connecting the exchanger, a refrigerant heater provided between the pipe and the other suction port of the compressor, and the outdoor heat exchanger during heating. 1. A heating and cooling system comprising: a frost detection means for detecting frost formation; and a control means for reducing the heat radiation amount of the indoor heat exchanger by a predetermined amount when the frost formation detection means detects frost formation. 2. A compressor having two inlets and one outlet, and two cylinder parts that operate simultaneously corresponding to each inlet, and an indoor heat exchanger installed indoors; an outdoor heat exchanger installed outdoors, a switching valve that connects each of the indoor heat exchangers and the outdoor heat exchanger to the discharge port and one suction port of the compressor, and a switching valve that connects the indoor heat exchanger and the outdoor heat Detecting frost formation on an expansion valve provided in a pipe connecting the exchanger, a refrigerant heater provided between the pipe and the other suction port of the compressor, and the outdoor heat exchanger during heating. 1. A heating and cooling device comprising: a frost detection means for detecting frost formation; and a control means for increasing the capacity of the refrigerant heater by a predetermined amount when the frost formation detection means detects frost formation.